FIELD OF DISCLOSURE
The present disclosure relates in general to refrigerators. Particularly, but not
exclusively, the present disclosure relates to load sensing technology in refrigerators.
More specifically, the present disclosure relates to a system for detecting load change
in refrigerators which improves the efficiency or functioning of refiigerators.
BACKGROUND OF THE DISCLOSURE
This section provides background information related to the present disclosure which
is not necessarily prior art.
In recent years, the focus of refrigerator manufacturers has become more inclined
towards the efficiency and environment friendliness of refrigerators. The manufactures
are also focused on producing low priced refrigerators yet not compromising on the
quality of cooling produced by them as well.
It is very much known that the highest power consuming component in a refrigerator is
the compressor. Also, the compressor has the major role to play in providing the cooling
effect in the refrigerator. It is also known that the existing refrigerators have a provision
of controlling the rate of working of compressor various means. Generally, the
refrigerator is incorporated with one or more sensors which provides signals to vary the
speed of the compressor through circuitry means thus affects the cooling capacity.
Conventionally, there are two sensors incorporated in the refrigerators i.e. each in the
fieezing unit and refrigerating unit. Generally, these sensors are present in all the no
frost (or frost free) refrigerators across the industries. However, such sensors cannot
control the compressor working rate efficiently thereby leading to excess power
consumption by the refrigerator.
Further, an additional ambient sensor in some refrigerators may be mounted on the
periphery of refrigerator body on the door panels to detect the real ambient temperature.
However, such ambient sensor cannot detect the load change and temperature change
in the unit in an efficient manner.
The present disclosure is directed to overcome one or more limitations as stated above
and any other problems associated with the prior arts.
SUMMARY OF DISCLOSURE
One or more shortcomings of conventional systems are overcome and additional
advantages are provided through the provision of system for detecting a load change in
a refrigerating unit as claimed in the present disclosure.
Additional features and advantages are realized through the techniques of the present
disclosure. Other embodiments and aspects of the disclosure are described in detail
herein and are considered a part of the claimed disclosure.
Accordingly, the present disclosure relates to a system for detecting load change in a
refrigerating unit. The system comprises an ambient sensor wherein the ambient sensor
is operatively coupled with an electronic control unit. The ambient sensor is configured
to detect the change in temperature of a condenser tube and provides an input signal to
the electronic control unit. The electronic control unit is configured to generate an
output signal for controlling the speed of a compressor thereby controlling the cooling
effect in the refrigerating unit.
In an embodiment, the ambient sensor is mounted on a hinge of a door of the
refrigerating unit.
In an embodiment, the ambient sensor is placed in thermal contact with the condenser
tubes.
In an embodiment, one or more layers of metallic plates are disposed between the
condenser tube and the ambient sensor to allow conduction of heat from the condenser
tube to the ambient sensor.
In an embodiment, the system forms a heat loop comprising of four layers wherein the
first layer is the condenser tube, the second layer is a cabinet surface ofthe refrigerating
unit, the third layer is the hinge and the fourth layer is the ambient sensor.
In an embodiment, the electronic control unit is operatively coupled with an auxiliary
sensor mounted in a refrigerating compartment of the refrigerating unit for detecting
the temperature of the refrigerating compartment.
In an embodiment, the electronic control unit is configured with a control logic with
pre-defined temperature patterns.
In an embodiment, the electronic control unit is coupled to a switching circuit to switch
supply of power from a power source for operating the compressor.
It is to be understood that the aspects and embodiments of the disclosure described
above may be used in any combination with each other. Several of the aspects and
embodiments may be combined together to form a further embodiment of the
disclosure.
The foregoing summary is illustrative only and is not intended to be in any way limiting.
In addition to the illustrative aspects, embodiments, and features described above,
further aspects, embodiments, and features will become apparent by reference to the
drawings and the following detailed description.
BRIEF DESCRIPTION OF FIGURES
The novel features and characteristics of the disclosure are set forth in the appended
claims. The disclosure itself, however, as well as a preferred mode of use, further
objectives and advantages thereof, will best be understood by reference to the following
detailed description of an illustrative embodiment when read in conjunction with the
accompanying drawings. One or more embodiments are now described, by way of
example only, with reference to the accompanying drawings wherein like reference
numerals represent like elements and in which:
Figures l(a)-l(b) illustrate a first sensor and a second sensor mounted in the
refrigerating unit and freezing unit respectively according to an embodiment of the
present disclosure.
Figure 2 illustrates an ambient sensor mounted on the condenser tube of the
refrigerating unit according to an embodiment of the present disclosure.
4
Figures 3(a)-3(b) illustrates the placement of the ambient sensor in the system for
detecting load change in the refrigerating unit according to an embodiment of the
present disclosure.
Figure 4 illustrates a schematic view depicting the location of the ambient sensor in the
system for detecting the load change in the refrigerating unit according to an
embodiment of the present disclosure.
Figure 5 illustrates a block diagram of the system for detecting the load change in the
refrigerating unit according to an embodiment of the present disclosure.
Figure 6 illustrates different seasonsiinput parameters defined in the control logic of
the system for detecting load change according to an embodiment of the present
disclosure.
The figures depict embodiments of the disclosure for purposes of illustration only. One
skilled in the art will readily recognize from the following description that alternative
embodiments of the structures and methods illustrated herein may be employed without
departing from the principles of the disclosure described herein.
DESCRIPTION OF DISCLOSURE
While the disclosure is susceptible to various modifications and alternative forms,
specific embodiment thereof has been shown by way of example in the figures and
will be described in detail below. It should be understood, however that it is not
intended to limit the disclosure to the particular forms disclosed, but on the contrary,
the disclosure is to cover all modifications, equivalents, and alternative falling within
the spirit and the scope of the present disclosure.
Before describing in detail embodiments it may be observed that the novelty and
inventive step that are in accordance with the present disclosure resides in the system
for detecting load change in the refrigerating unit. It is to be noted that a person skilled
in the art can be motivated from the present disclosure and modify the various
constructions, which are varying from refrigerating device to refrigerating device.
However, such modification should be construed within the scope and spirit of the
disclosure. Accordingly, the drawings are showing only those specific details that are
5
pertinent to understanding the embodiments of the present disclosure so as not to
obscure the disclosure with details that will be readily apparent tothose of ordinary
skill in the art having benefit of the description herein.
The terms "comprises", "comprising", or any other variations thereof, are intended
to cover a non-exclusive inclusion, such that a setup, device that comprises a list of
components does not include only those components but may include other
components not expressly listed or inherent to such setup or device. In other words,
one or more elements in a system or apparatus proceeded by "comprises.. . a" does
not, without more constraints, preclude the existence of other elements or additional
elements in the system or apparatus.
The present disclosure relates to a system for detecting or sensing load change
incorporated in a refrigerating unit wherein an ambient sensor senses the load change
or temperature of the condenser tube of refrigerating unit. Whenever a load change
occurs due to opening of a door of the refrigeration unit, a change in temperature of a
condenser tube takes place. In an embodiment, the ambient sensor of the present system
will sense the change in temperature of the condenser tube and provides output for
varying compressor speed.
The following paragraphs describe the present disclosure with reference to Figures 1 to
6. In the figures the same element or elements which have same functions are indicated
by the same reference signs.
Referring to Figures l(a)-(b), the refrigerating unit (100) has two compartments namely
a freezing compartment (50) and a refrigerating compartment (60). The freezing
compartment (60) comprises of a freezing compartment sensor (i.e. also referred herein
as 'first sensor (1)') mounted on evaporator tubes (not shown in Figures). The first
sensor (1) provides a feedback for operating a heater (not shown) in the refrigerating
unit (100) for the process of defrosting. When the refrigerating unit (100) is in working
condition, as per control logic, refrigerating unit goes to defrost after a specified period
of compressor (20). Once the process of defrost has started the heater will be in on
condition, till the temperature of the freezing compartment (50) increases to a higher
temperature. Once this higher temperature is achieved, the first sensor (1) gives
feedback to stop the heater.
6
The refrigerating compartment sensor (i.e. also termed as a second sensor (2)) is placed
inside the refrigerating compartment (60) of the refrigerating unit (100). The second
sensor (2) can also be termed as an 'auxiliary sensor' in the description. The second
sensor (2) works according to a predefined control logic (12) as shown in Figure 6. The
input parameters include predefined set points as shown in Figure 6. The primary
function of the second sensor (2) is based on said pre-defined set points and thereby
providing signals to start or stop the compressor.
Referring to Figure 2, the present disclosure provide system for detecting a load change
in the refrigerating unit (R). The present system for detecting load change comprises of
a third temperature sensor (also referred herein as 'ambient sensor'). As can be clearly
understood that the first second and third sensors referred herein above are the
temperature sensors.
In an embodiment as shown in Detail A, the third sensor (3) may be configured on a
door hinge (13) of the refrigerating unit (R) and may be placed in thermal contact with
condenser tubes (14) as shown in Figures 3(a)-3(b). The term 'thermal contact' herein
refers to a contact which enable transfer of heat by conduction. As can be understood
that one or more layers may be present between the third sensor and the condenser tube.
The said one or more layer may include a metal hinge and the metallic surfacelportion
of the door to allow conduction of heat from condenser tube to the third sensor. Thus,
the third sensor (3) detects the temperature of the condenser tube (14) (also referred
herein to as 'heat loop').
In an embodiment, the third sensor (3) is an ambient sensor. As the load change in the
refrigerating unit occurs due to opening of the door as the ambient air enters the
refrigerating unit (R), the condenser tube (14) temperature increases. The change in
temperature of condenser tube is detected by the third sensor which give output for
increasing the compressor (20) run.
According to an embodiment of the present disclosure as shown in Figure 4, the system
for detecting load change in the refrigerating unit comprises of four layers wherein, the
first layer is the condenser tube (14), the second layer is a cabinet surface (16) of the
refrigerating unit (R), the third layer is the hinge (13) (i.e. a metal) and the fourth layer
is the third sensor (3). The third sensor (3) is further covered from outside by metallic
7
material of the cabinet of the refrigerating unit. As explained in previous paragraphs,
the heat transfer from the condenser tube (14) to the third sensor (3) occurs by
conduction. Since, the first three layers of the present system of load sensing are of
metallic material, the mode of heat transfer is faster and the heat of heat loop or
condenser tube (14) is transferred almost as it is to the third sensor (3). The temperature
of heat loop (14) is always higher than ambient temperature and also it changes based
on addition/removal of heat load.
In an embodiment, in the present system for detecting load change, the third sensor (3)
is disposed on the hinge (13) near the condenser tube (14), wherein the hinge (13) in
contact with the cabinet metal surface (16) of the refrigerating unit (R) and the cabinet
surface (16) is in contact with heat loop i.e. the condenser tube (14) from inside. When
the door of the refrigerating unit is opened or there is a load change, the temperature of
the condenser tube (14) increases due to increase in thermal load since the temperature
of the condenser tube is always higher than the ambient temperature and the same can
be sensed by the third sensor (3). Based on this input, the variable capacity compressor
(20) changes its speed, thereby increasing the speed of cooling. Since as per heat transfer
theory condensing tube temperature is always higher than ambient temperature, the third
sensor (3) will sense the temperature from condenser tube (14). For example, when the
ambient temperature is in the range of -32C, condenser tube temperature will be 6-8C
higher than ambient temperature [(again this delta (i.e. difference in ambient to
condenser tube temperatures)] is not constant as it always depends on inside load and
actual ambient temperature). Therefore, the third sensor in the present system of
detecting load change will always detect the temperature ofthe condenser tube (14).
Referring to Figure 5, the system for detecting load change comprises an Electronic
Control Unit (ECU) operative coupled with the second sensor (2) and the third sensor
(3). The ECU (21) is configured with a predefined control logic (12). In an embodimenf
in the control logic one or more seasons namely Season 1, Season 2, Season 3 and
Season 4 may be defined (as shown in Figure 6). However, said defined parameters
will always be dependent on performance requirement of the refrigerating unit (R).
Based on the change in heat loop temperature, the third sensor (3) gives input to the
ECU (21). The input received from the second sensor and the third sensor, the ECU
(21), based on the control logic (12), provides signals to control the operation of the
8
compressor (20) resulting in required cooling and effective energy consumption. In an
embodiment, the ECU (21) is coupled with a switching circuit and the ECU (21)
provides an output to a switching circuit (23) to switch on supply of power from a power
source (22) for operating the compressor (20).
The third sensor (3) detects temperature from condenser tube (it is generated from
thermal load of the refrigerating unit). It gives real sense of load change and door
opening impact, thereby increasing the speed of compressor (20) to make faster cooling.
The proposed load sensing technology configuration always senses temperatures based
on door openings1 and subsequent thermal load impact.
As shown in Figure 5, in an embodiment of the present disclosure, the compressor
power andlor speed is controlled based on input from the second sensor (2) and third
sensor (3) based on control logic (12).
Further, various modifications and variations may be made without departing from the
scope of the present invention. Therefore, it is intended that the present disclosure
covers such modifications and variations provided they come within the ambit of the
appended claims and their equivalents.
EOUIVALENTS:
With respect to the use of substantially any plural andor singular terms herein, those
having skill in the art can translate from the plural to the singular and/or from the
singular to the plural as is appropriate to the context and/or application. The various
singularlplural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and
especially in the appended description (e.g., bodies of the appended description) are
generally intended as "open" terms (e.g., the term "including" should be interpreted as
"including but not limited to," the term "having" should be interpreted as "having at
least," the term "includes" should be interpreted as "includes but is not limited to," etc.).
It will be further understood by those within the art that if a specific number of an
introduced claim recitation is intended, such an intent will be explicitly recited in the
claim, and in the absence of such recitation no such intent is present. For example, as
an aid to understanding, the following appended description may contain usage of the
9
introductory phrases "at least one" and "one or more" to introduce claim recitations.
However, the use of such phrases should not be construed to imply that the introduction
of a claim recitation by the indefinite articles "a" or "an" limits any particular claim
containing such introduced claim recitation to disclosures containing only one such
recitation, even when the same claim includes the introductory phrases "one or more"
or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should
typically be interpreted to mean "at least one" or "one or more"); the same holds true
for the use of definite articles used to introduce claim recitations. In addition, even if a
specific number of an introduced claim recitation is explicitly recited, those skilled in
the art will recognize that such recitation should typically be interpreted to mean at least
the recited number (e.g., the bare recitation of "two recitations," without other
modifiers, typically means at least two recitations, or two or more recitations).
Furthermore, in those instances where a convention analogous to "at least one of A, B,
and C, etc." is used, in general such a construction is intended in the sense one having
skill in the art would understand the convention (e.g., "a system having at least one of
A, B, and C" would include but not be limited to systems that have A alone, B alone, C
alone, A and B together, A and C together, B and C together, and/or A, B, and C
together, etc.). In those instances where a convention analogous to "at least one of A,
B, or C, etc." is used, in general such a construction is intended in the sense one having
skill in the art would understand the convention (e.g., "a system having at least one of
A, B, or C" would include but not be limited to systems that have A alone, B alone, C
alone, A and B together, A and C together, B and C together, and/or A, B, and C
together, etc.). It will be further understood by those within the art that virtually any
disjunctive word and/or phrase presenting two or more alternative terms, whether in the
description or drawings, should be understood to contemplate the possibilities of
including one of the terms, either of the terms, or both terms. For example, the phrase
"A or B" will be understood to include the possibilities of "A" or "B" or "A and B."
While various aspects and embodiments have been disclosed herein, other aspects and
embodiments will be apparent to those skilled in the art. The various aspects and
embodiments disclosed herein are for purposes of illustration and are not intended to
be limiting, with the true scope and spirit being indicated by the description.
List of Reference Numerals
Refrigerating Unit (R)
Freezing Compartment (50)
Refrigerating Compartment (60)
First Sensor (1)
Second Sensor (2)
ThirdIArnbient Sensor (3)
Control logic (12)
Hinge (13)
Condenser tube (14)
Door (1 5)
Cabinet Surface (16)
Compressor (20)
Electronic control unit (21)
Power Source (22)
Switching Circuit (23)

Claim:
1. A system for detecting a load change in a refrigerating unit (R), the said system
comprising;
an ambient sensor (3);
wherein the ambient sensor (3) is operatively coupled with an electronic control
unit (2 1);
wherein the ambient sensor (3) is configured to detect the change in temperature
of a condenser tube (14) and providing an input signal to the electronic control
unit (21);
wherein the electronic control unit (21) is configured to generate an output
signal for controlling the speed of a compressor (20) thereby controlling the
cooling effect in the refrigerating unit (R).
2. The system as claimed in claim 1, wherein the ambient sensor (3) is mounted on a
hinge (13) of a door (15) of the refrigerating unit (R).
3. The system as claimed in claim I , wherein the ambient sensor (3) is placed in thermal
contact with the condenser tubes (14).
4. The system as claimed in claim 1, wherein one or more layers of metallic plates are
disposed between the condenser tube (14) and the ambient sensor (3) to allow
conduction of heat from the condenser tube (14) to the ambient sensor (3).
5. The system as claimed in claim 1, wherein the system forms a heat loop comprising
of four layers wherein the first layer is the condenser tube (14), the second layer is a
cabinet surface (16) of the refrigerating unit (R), the third layer is the hinge (13) and
the fourth layer is the ambient sensor (3).
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6. The system as claimed in claim 1, wherein the electronic control unit (21) is
operatively coupled with an auxiliary sensor (2) mounted in a refrigerating
compartment (60) of the refrigerating unit (R) for detecting the temperature of the
refrigerating compartment (R).
7. The system as claimed in claim 1, wherein the electronic control unit (21) is
configured with a control logic (12) with pre-defined temperature patterns.
8. The system as claimed in claim I, wherein the electronic control unit (21) is coupled
to a switching circuit (23) to switch supply of power from a power source (22) for
operating the compressor (20).